During the manufacture of an array substrate, such a phenomenon as electro-static discharge (ESD) may inevitably occur due to the movement of the array substrate on a machine table as well as the manufacturing process. Due to accumulation of electrostatic electricity, an obvious potential difference may be formed between conductors on the array substrate. A high voltage or current may be generated instantaneously once the ESD occurs, and then the performance of a semiconductor layer or metal wires on the array substrate may be degraded, and even the semiconductor layer or the metal wires may be damaged. As a result, the performance of the array substrate may be degraded and even the array substrate may be damaged too, and the yield thereof may be adversely affected.
In the related art, there are the following electrostatic protection methods for the array substrate.
1. A protection circuit including a thin film transistor (TFT) may be provided. When a large voltage is applied to the TFT, a current outputted by the TFT may increase exponentially, and then an impact current generated by the ESD is discharged through the TFT to a reference level or a large resistance-capacitance network.
2. A plurality of point-discharge points may be provided. After a point discharge pattern is formed, the electrostatic electricity in the proximity of the point discharge pattern may be discharged via the point-discharge points, so as to protect the wires.
However, the above methods have following defects.
1. When the electrostatic protection adopts the protection circuit, the electrostatic protection depends on the formation of the TFT. Generally speaking, the formation of the TFT at least includes depositing two metal layers and dry-etching an insulation layer, and it is impossible to prevent the occurrence of the electrostatic electricity in manufacturing processes before the formation of the TFT. In some manufacturing processes, the protection circuit is formed at the end of the whole manufacturing process, and at this point, the protection circuit does not make much sense in the elimination of the electrostatic electricity generated during the manufacture of the array substrate.
2. When the point-discharge points are adopted, the electrostatic electricity is discharged only when a breakdown field generated by the metallic points is sufficient for the breakdown of the insulation layer. The electrostatic electricity is discharged at a random position and at a random amount, and meanwhile it is very difficult to ensure the electrostatic discharge each time.